AgingNCT05482711
The Fuel and Rhythm (FAR) Phase 2 Study
A study testing Time Restricted Eating Intervention in people with Aging, run by University of Florida at 1 site in United States.
Trial summary
Both fuel metabolism and circadian rhythms have emerged as important targets to improve cellular and mitochondrial health and ultimately affect function in older adults. Thus, the purpose of this study is to develop minimally invasive measures that will allow us to accurately assess and detect changes in fuel… Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Aging
- What is being tested?
- Time Restricted Eating Intervention
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Jan 2023to 28 Feb 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Consent to participate in the study
- Men and women ≥ 65 years old
- Self-reported difficulty walking ¼ mile or climbing a flight of stairs
- Self-reported sedentariness (<150 minutes structured exercise per week)
- Walking speed <1 m/sec on the 4 m walk test
- Able to walk unassisted (cane allowed)
- Have a body mass index between 25 - 40 kg/m2 (inclusive)
- HbA1c < 5.7 %
Who cannot join
- Fasting >12 hours per day
- Actively trying to lose weight by participating in formal weight loss program or significantly restricting calorie intake
- Resting heart rate of >120 beats per minute, systolic blood pressure > 180 mmHg and/or diastolic blood pressure of > 100 mmHg
- Unstable angina, heart attack or stroke in the past 3 months
- Continuous use of supplemental oxygen to manage a chronic pulmonary condition or heart failure
- Rheumatoid arthritis, Parkinson's disease or currently on dialysis
Show all 11Show fewer
- Active treatment for cancer in the past year
- Diabetes Mellitus
- Known history of skin sensitivity or allergic reaction to adhesives
- Taking medications that preclude fasting for 16 hours (e.g. must be taken with food at least 12 hours apart)
- Any condition that in the opinion of the investigator would impair ability to participate in the trial
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessment of Fuel Utilization and Circadian Rhythms in Overweight, Older Adults Following Time Restricted Eating - Phase 2 (FAR Phase 2)
Both fuel metabolism and circadian rhythms have emerged as important targets to improve cellular and mitochondrial health and ultimately affect function in older adults. Thus, the purpose of this study is to develop minimally invasive measures that will allow us to accurately assess and detect changes in fuel metabolism and circadian rhythms in older adults following time-restricted eating.
Read the detailed description
A growing body of evidence indicates the mitochondria have an important role in the etiologies of many chronic diseases as well as the onset of physical disability in older adults. Although it is recognized that the mitochondria have an important role in many functions relevant to healthy aging, the direct assessment of mitochondrial function in humans is complicated and typically involves a muscle biopsy. Muscle tissue obtained from a biopsy can be used to provide an index of mitochondrial function, but only at a single time point. Some individuals may be discouraged from participating in research studies involving biopsies due to the perceived pain and risk involved.
Why there is a decrease in mitochondrial function with aging remains under debate, but emerging science indicates that there is a clear connection between mitochondrial biogenesis and function with fuel metabolism and circadian rhythms. Thus, the purpose of this development project is to develop relatively non-invasive measures that are sensitive to fuel metabolism and circadian health which can serve studies conducted within the University of Florida's Pepper Center in the coming years. In the proposed project, we will investigate the extent to which our measures of fuel utilization and circadian health markers are time stable and also sensitive to change following an intervention of time restricted eating, which is expected to impact these variables.
To our knowledge, no study has assessed fuel utilization patterns or circadian health markers in overweight older adults. Measurements of altered mitochondrial oxidation with a preference toward fat metabolism obtained from a blood sample would provide a sensitive biomarker that is relatively easy to obtain from participants for future interventions studies. The use of continuous glucose monitoring may also be used as surrogate measure of adherence to lifestyle interventions involving calorie restriction and/or intervention fasting, in future studies.
In addition to fuel utilization, there is growing recognition that age-related disease conditions and functional decline are associated with disruption of circadian rhythms. These observations raise the possibility that targeting circadian rhythms through timing lifestyle cues, such as meal timing, could be health promoting and may also reduce age associated declines in mobility. The ability to assess markers of circadian and metabolic health in minimally invasive ways through temperature and glucose monitoring, will provide potential valuable measures for explanatory or outcome measures in future studies.
- Conditions
- Aging
- Being tested
- Time Restricted Eating Intervention
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Time Restricted Eating InterventionOther
All participants will be asked to adhere to suggested fasting and feeding periods throughout the 8 week study period. These participants will self-monitor eating and sleeping habits as well to present to study staff at checkpoints. Self-reported information will be used during group-mediated intervention sessions throughout the duration of the study, as well.
| Study group | Role | What they receive |
|---|---|---|
| Time Restricted Eating intervention | Other | Participants will be asked to stop eating by 7 PM every day and to fast for a target of 16 hours per day for 8 weeks. During the first two weeks of the intervention, participants will gradually ramp up to a full 16-hour fasting period (Week 1 - fast for 12-14 hours per day, Week 2 - fast for 14-16 hours per day, Week 3 - 8 - fast for 16 hours per day). Participants will be allowed to consume calorie-free beverages, tea, black coffee, sugar-free gum, and they will be encouraged to drink plenty of water throughout the entire intervention period. Additionally, they will be asked to keep a Fasting and Sleeping diary logging their eating habits and sleep quality. Receives: Other: Time Restricted Eating Intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Cellular Fuel Utilization
Fuel preference for mitochondrial energy production of isolated white blood cells (WBC) will be assessed using Agilent/Seahorse technology (XFe96 Flux Analyzer) for high-throughput measurement of mitochondrial oxygen bioenergetic function. We will use the Mito Fuel Flex Test assay (Agilent/Seahorse) to measure basal state mitochondrial fuel oxidation in live cells by using a set of substrates and inhibitors. This assay allows assessing the cell's ability to switch oxidative pathways in meeting basal energetic demands, and the relative contributions of glucose, glutamine and long chain fatty acid oxidation to basal respiration. This is completed by a 12-hour fasting blood draw.
Measured: Assessing change between Baseline and Week 8
Change in daily blood glucose levels
A "flash glucose monitor/sensor" (CGM; FreeStyle Libre PRO) will be used to assess the changes in 24-hour blood glucose levels. The FreeStyle Libre sensor is easy to apply and wear and can provide every five-minute glucose data to research monitors for up to 14 days. We will replace the CGM approximately every 2 weeks. In this study, we will use the Freestyle PRO thus the participants will be blinded to the data. We will evaluate pattern changes in daily glycemic excursions by week of the study as well as weekly averages and standard deviation by 6-hour time block.
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene BMAL1
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Bmal1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in Heart rate will be assessed by the Oura ring.
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that continuously tracks heart rate (beats per minute). The Oura ring is a Bluetooth Smart device and is only active for short periods of time. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene CLOCK
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of CLOCK will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in body temperature will be assessed by the Oura ring.
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that tracks body temperature in Fahrenheit (°F). The Oura ring is a Bluetooth Smart device and is only active for short periods of time. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Measured: Assessing change between Baseline and Week 8
Change in activity level will be assessed by the Oura ring.
This development measure aims to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that provides daily activity level scores. The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be given an Oura ring and instructed to wear it for the entire course of the study.
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene Nfil2
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Nfil2 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene Nr1d1
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Nr1d1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene Dbp
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Dbp will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene Cry1
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Cry1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in circadian rhythm gene Per2
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Per2 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Measured: Assessing change between Baseline and Week 8
Change in heart rate variability will be assessed by the Oura ring.
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that tracks heart rate variability (HRV) in milliseconds (ms). The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Measured: Assessing change between Baseline and Week 8
Change in sleep patterns will be assessed by the Oura ring.
This development measure aims to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that provides sleep patterns scores. The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with an Oura ring and instructed to wear it for the entire course of the study.
Measured: Assessing change between Baseline and Week 8
Secondary outcomes (10)
Change in anthropometric measurements
Height is measured in centimeters (cm) using a stadiometer. Bodyweight will be measured in kilograms (kg) following the removal of excess clothing and shoes with calibrated scales. Weight and height will be combined to report BMI in kg/m^2. Waist circumference is taken at the mid-point (cm) between the participant's lowest rib and the top of the participants' hip bone.
Measured: Assessing change between Baseline and Week 8
Change in Body Composition
Body composition analysis will be performed in lower and upper body compartments using Hologic software. Values of fat-free mass (FFM) will be calculated after removing mass due to bone mineral content (BMC) using the equation, (FFM+BMC)-BMC=FFM.
Measured: Assessing change between Baseline and Week 8
Change in walking speed.
Walking Speed will be assessed by the 6 Minute Walk test. The 6 Minute Walk test is a valid and reliable measure of physical function in numerous studies. Individuals will be asked to walk as quickly and safely as possible at a pace that can be maintained for six minutes. The distance completed in 6 minutes will be recorded. The 6 Minute Walk test will be administered by a trained examiner.
Measured: Assessing change between Baseline and Week 8
Change in grip strength
Isometric handgrip strength is a commonly used measure of upper body skeletal muscle function and is widely used as a general indicator of functional status.
Measured: Assessing change between Baseline and Week 8
Change in Whole Body Fuel Utilization
Participants will be fitted with a mask and harness and oxygen consumption and carbon dioxide production will be measured using a portable Cosmed K5. Participants will be asked to refrain from volitional exercise for the prior 24 hrs and come into the lab after an overnight fast. The mask will be placed over the mouth and nose in a thermoneutral environment. Resting metabolic rate (RMR) will be collected for 45 min and the final 30 min of data will be averaged. Movement or sleeping during the test will be noted, and these time periods will be excluded from RMR calculation using the Weir formula. RMR values will be adjusted for lean mass. Respiratory quotient (RQ) will be calculated as carbon dioxide (CO2) produced divided by oxygen (O2) consumed, protein oxidation during stable evaluation (within a coefficient of variation (CV) <5%). A high RQ closer to 1.0 indicates more carbohydrate production whereas the RQ for fat is 0.7 and for ketones is 0.66 (hypocaloric) to 0.73 (eucaloric).
Measured: Assessing change between Baseline and Week 8
Change in Cognitive Function - Memory
A valid cognitive battery (NIH Toolbox) will be used in this study to assess an aspect of cognitive performance including memory.
Measured: Assessing change between Baseline and Week 8
Change in Physical Function
Physical Function be assessed by the Short Physical Performance Battery to assess functional performance on different tasks including timed short distance walk, repeated chair stands, and a balance test. The Short Physical Performance Battery will be administered by a trained examiner
Measured: Assessing change between Baseline and Week 8
Change in Cognitive Function - Processing speed
A valid cognitive battery (NIH Toolbox) will be used in this study to assess an aspect of cognitive performance including processing speed.
Measured: Assessing change between Baseline and Week 8
Chang in Cognitive Function - Attention
A valid cognitive battery (NIH Toolbox) will be used in this study to assess an aspect of cognitive performance including attention.
Measured: Assessing change between Baseline and Week 8
Change in Cognitive Function - Inhibitory Control
A valid cognitive battery (NIH Toolbox) will be used in this study to assess an aspect of cognitive performance including inhibitory control.
Measured: Assessing change between Baseline and Week 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Aug 2022
- Study start10 Jan 2023
- Primary completion31 Aug 2025
- Study completion28 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (35)Papers the sponsor has linked to this study.
- Other trials for AgingStudies of the same condition, open and under way.
- More trials run by University of FloridaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Aging (NIA)
- Responsible party
- Sponsor
- Investigators
- Stephen Anton, Ph.D., Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05482711
- Sponsor's protocol ID
- IRB202102618 -N
- Other IDs
- P30AG028740
- Status last verified
- Mar 2026
- First submitted
- 11 Jul 2022
- Last updated
- 30 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Information on the study protocol may be provided upon request.
Publications
Sardon Puig L, Valera-Alberni M, Canto C, Pillon NJ. Circadian Rhythms and Mitochondria: Connecting the Dots. Front Genet. 2018 Oct 8;9:452. doi: 10.3389/fgene.2018.00452. eCollection 2018.
PubMed 30349557Kohsaka A, Das P, Hashimoto I, Nakao T, Deguchi Y, Gouraud SS, Waki H, Muragaki Y, Maeda M. The circadian clock maintains cardiac function by regulating mitochondrial metabolism in mice. PLoS One. 2014 Nov 12;9(11):e112811. doi: 10.1371/journal.pone.0112811. eCollection 2014.
PubMed 25389966Kuzmiak-Glancy S, Willis WT. Skeletal muscle fuel selection occurs at the mitochondrial level. J Exp Biol. 2014 Jun 1;217(Pt 11):1993-2003. doi: 10.1242/jeb.098863. Epub 2014 Mar 13.
PubMed 24625643Anton S, Leeuwenburgh C. Fasting or caloric restriction for healthy aging. Exp Gerontol. 2013 Oct;48(10):1003-5. doi: 10.1016/j.exger.2013.04.011. Epub 2013 Apr 29.
PubMed 23639403Alexeyev MF. Is there more to aging than mitochondrial DNA and reactive oxygen species? FEBS J. 2009 Oct;276(20):5768-87. doi: 10.1111/j.1742-4658.2009.07269.x.
PubMed 19796285Anton SD, Moehl K, Donahoo WT, Marosi K, Lee SA, Mainous AG 3rd, Leeuwenburgh C, Mattson MP. Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity (Silver Spring). 2018 Feb;26(2):254-268. doi: 10.1002/oby.22065. Epub 2017 Oct 31.
PubMed 29086496Ferrucci L, Guralnik JM, Pahor M, Corti MC, Havlik RJ. Hospital diagnoses, Medicare charges, and nursing home admissions in the year when older persons become severely disabled. JAMA. 1997 Mar 5;277(9):728-34.
PubMed 9042845Fried LP, Guralnik JM. Disability in older adults: evidence regarding significance, etiology, and risk. J Am Geriatr Soc. 1997 Jan;45(1):92-100. doi: 10.1111/j.1532-5415.1997.tb00986.x.
PubMed 8994496Manini T. Development of physical disability in older adults. Curr Aging Sci. 2011 Dec;4(3):184-91. doi: 10.2174/1874609811104030184.
PubMed 21529321Chung HY, Cesari M, Anton S, Marzetti E, Giovannini S, Seo AY, Carter C, Yu BP, Leeuwenburgh C. Molecular inflammation: underpinnings of aging and age-related diseases. Ageing Res Rev. 2009 Jan;8(1):18-30. doi: 10.1016/j.arr.2008.07.002. Epub 2008 Jul 18.
PubMed 18692159Boengler K, Kosiol M, Mayr M, Schulz R, Rohrbach S. Mitochondria and ageing: role in heart, skeletal muscle and adipose tissue. J Cachexia Sarcopenia Muscle. 2017 Jun;8(3):349-369. doi: 10.1002/jcsm.12178. Epub 2017 Apr 21.
PubMed 28432755Tarasov AI, Griffiths EJ, Rutter GA. Regulation of ATP production by mitochondrial Ca(2+). Cell Calcium. 2012 Jul;52(1):28-35. doi: 10.1016/j.ceca.2012.03.003. Epub 2012 Apr 12.
PubMed 22502861Volobueva AS, Melnichenko AA, Grechko AV, Orekhov AN. Mitochondrial genome variability: the effect on cellular functional activity. Ther Clin Risk Manag. 2018 Feb 9;14:237-245. doi: 10.2147/TCRM.S153895. eCollection 2018.
PubMed 29467576Settembre C, Ballabio A. Lysosome: regulator of lipid degradation pathways. Trends Cell Biol. 2014 Dec;24(12):743-50. doi: 10.1016/j.tcb.2014.06.006. Epub 2014 Jul 21.
PubMed 25061009Larsen S, Hey-Mogensen M, Rabol R, Stride N, Helge JW, Dela F. The influence of age and aerobic fitness: effects on mitochondrial respiration in skeletal muscle. Acta Physiol (Oxf). 2012 Jul;205(3):423-32. doi: 10.1111/j.1748-1716.2012.02408.x. Epub 2012 Feb 11.
PubMed 22212519
Study at a glance
From the registry record, last updated by the sponsor on 30 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Fuel Utilization and Circadian Rhythms in Overweight, Older Adults Following Time Restricted Eating - Phase 2 (FAR Phase 2)
- ClinicalTrials.gov ID
- NCT05482711
- Acronym / sponsor ID
- IRB202102618 -N
- Conditions
- Aging
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Collaborators
- National Institute on Aging (NIA)
- Study start
- 10 Jan 2023 (actual)
- Primary completion
- 31 Aug 2025 (actual)
- Study completion
- 28 Feb 2026 (actual)
- First posted
- 1 Aug 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Both fuel metabolism and circadian rhythms have emerged as important targets to improve cellular and mitochondrial health and ultimately affect function in older adults. Thus, the purpose of this study is to develop minimally invasive measures that will allow us to accurately assess and detect changes in fuel metabolism and circadian rhythms in older adults following time-restricted eating.
Detailed description
A growing body of evidence indicates the mitochondria have an important role in the etiologies of many chronic diseases as well as the onset of physical disability in older adults. Although it is recognized that the mitochondria have an important role in many functions relevant to healthy aging, the direct assessment of mitochondrial function in humans is complicated and typically involves a muscle biopsy. Muscle tissue obtained from a biopsy can be used to provide an index of mitochondrial function, but only at a single time point. Some individuals may be discouraged from participating in research studies involving biopsies due to the perceived pain and risk involved.
Why there is a decrease in mitochondrial function with aging remains under debate, but emerging science indicates that there is a clear connection between mitochondrial biogenesis and function with fuel metabolism and circadian rhythms. Thus, the purpose of this development project is to develop relatively non-invasive measures that are sensitive to fuel metabolism and circadian health which can serve studies conducted within the University of Florida's Pepper Center in the coming years. In the proposed project, we will investigate the extent to which our measures of fuel utilization and circadian health markers are time stable and also sensitive to change following an intervention of time restricted eating, which is expected to impact these variables.
To our knowledge, no study has assessed fuel utilization patterns or circadian health markers in overweight older adults. Measurements of altered mitochondrial oxidation with a preference toward fat metabolism obtained from a blood sample would provide a sensitive biomarker that is relatively easy to obtain from participants for future interventions studies. The use of continuous glucose monitoring may also be used as surrogate measure of adherence to lifestyle interventions involving calorie restriction and/or intervention fasting, in future studies.
In addition to fuel utilization, there is growing recognition that age-related disease conditions and functional decline are associated with disruption of circadian rhythms. These observations raise the possibility that targeting circadian rhythms through timing lifestyle cues, such as meal timing, could be health promoting and may also reduce age associated declines in mobility. The ability to assess markers of circadian and metabolic health in minimally invasive ways through temperature and glucose monitoring, will provide potential valuable measures for explanatory or outcome measures in future studies.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Time Restricted Eating intervention | Other | Other: Time Restricted Eating InterventionParticipants will be asked to stop eating by 7 PM every day and to fast for a target of 16 hours per day for 8 weeks. During the first two weeks of the intervention, participants will gradually ramp up to a full 16-hour fasting period (Week 1 - fast for 12-14 hours per day, Week 2 - fast for 14-16 hours per day, Week 3 - 8 - fast for 16 hours per day). Participants will be allowed to consume calorie-free beverages, tea, black coffee, sugar-free gum, and they will be encouraged to drink plenty of water throughout the entire intervention period. Additionally, they will be asked to keep a Fasting and Sleeping diary logging their eating habits and sleep quality. |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (8 listed)
- Consent to participate in the study
- Men and women ≥ 65 years old
- Self-reported difficulty walking ¼ mile or climbing a flight of stairs
- Self-reported sedentariness (<150 minutes structured exercise per week)
- Walking speed <1 m/sec on the 4 m walk test
Key exclusion criteria (11 listed)
- Fasting >12 hours per day
- Actively trying to lose weight by participating in formal weight loss program or significantly restricting calorie intake
- Resting heart rate of >120 beats per minute, systolic blood pressure > 180 mmHg and/or diastolic blood pressure of > 100 mmHg
- Unstable angina, heart attack or stroke in the past 3 months
- Continuous use of supplemental oxygen to manage a chronic pulmonary condition or heart failure
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Time Restricted Eating InterventionAll participants will be asked to adhere to suggested fasting and feeding periods throughout the 8 week study period. These participants will self-monitor eating and sleeping habits as well to present to study staff at checkpoints. Self-reported information will be used during group-mediated intervention sessions throughout the duration of the study, as well. | Other | Time Restricted Eating intervention |
Primary outcome
Change in Cellular Fuel Utilization
Time frame: Assessing change between Baseline and Week 8
Fuel preference for mitochondrial energy production of isolated white blood cells (WBC) will be assessed using Agilent/Seahorse technology (XFe96 Flux Analyzer) for high-throughput measurement of mitochondrial oxygen bioenergetic function. We will use the Mito Fuel Flex Test assay (Agilent/Seahorse) to measure basal state mitochondrial fuel oxidation in live cells by using a set of substrates and inhibitors. This assay allows assessing the cell's ability to switch oxidative pathways in meeting basal energetic demands, and the relative contributions of glucose, glutamine and long chain fatty acid oxidation to basal respiration. This is completed by a 12-hour fasting blood draw.
Change in daily blood glucose levels
Time frame: Assessing change between Baseline and Week 8
A "flash glucose monitor/sensor" (CGM; FreeStyle Libre PRO) will be used to assess the changes in 24-hour blood glucose levels. The FreeStyle Libre sensor is easy to apply and wear and can provide every five-minute glucose data to research monitors for up to 14 days. We will replace the CGM approximately every 2 weeks. In this study, we will use the Freestyle PRO thus the participants will be blinded to the data. We will evaluate pattern changes in daily glycemic excursions by week of the study as well as weekly averages and standard deviation by 6-hour time block.
Change in circadian rhythm gene BMAL1
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Bmal1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in Heart rate will be assessed by the Oura ring.
Time frame: Assessing change between Baseline and Week 8
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that continuously tracks heart rate (beats per minute). The Oura ring is a Bluetooth Smart device and is only active for short periods of time. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Change in circadian rhythm gene CLOCK
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of CLOCK will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in body temperature will be assessed by the Oura ring.
Time frame: Assessing change between Baseline and Week 8
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that tracks body temperature in Fahrenheit (°F). The Oura ring is a Bluetooth Smart device and is only active for short periods of time. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Change in activity level will be assessed by the Oura ring.
Time frame: Assessing change between Baseline and Week 8
This development measure aims to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that provides daily activity level scores. The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be given an Oura ring and instructed to wear it for the entire course of the study.
Change in circadian rhythm gene Nfil2
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Nfil2 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in circadian rhythm gene Nr1d1
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Nr1d1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in circadian rhythm gene Dbp
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Dbp will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in circadian rhythm gene Cry1
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Cry1 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in circadian rhythm gene Per2
Time frame: Assessing change between Baseline and Week 8
Whole blood will be collected in Tempus™ Blood RNA Tubes with RNA isolated using the Tempus™ Spin RNA Isolation Kit according to the manufacturer (Applied Biosystems). Relative gene expression of Per2 will be analyzed using quantitative real-time polymerase chain reaction (PCR).
Change in heart rate variability will be assessed by the Oura ring.
Time frame: Assessing change between Baseline and Week 8
The goal of this development measure is to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that tracks heart rate variability (HRV) in milliseconds (ms). The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with Oura ring and instructed to wear it for the entire course of the study.
Change in sleep patterns will be assessed by the Oura ring.
Time frame: Assessing change between Baseline and Week 8
This development measure aims to create a composite measure of circadian health using Wearable Technology (i.e., the Oura ring) that provides sleep patterns scores. The Oura ring is a Bluetooth Smart device and is only active for short periods. Data is transmitted continuously when the ring syncs with the app. Additionally, the Bluetooth signal and advertising are turned off when an individual is inactive or sleeping. Participants will be provided with an Oura ring and instructed to wear it for the entire course of the study.
10 secondary outcomes
Change in anthropometric measurements
Time frame: Assessing change between Baseline and Week 8
Change in Body Composition
Time frame: Assessing change between Baseline and Week 8
Change in walking speed.
Time frame: Assessing change between Baseline and Week 8
Change in grip strength
Time frame: Assessing change between Baseline and Week 8
Change in Whole Body Fuel Utilization
Time frame: Assessing change between Baseline and Week 8
Change in Cognitive Function - Memory
Time frame: Assessing change between Baseline and Week 8
Change in Physical Function
Time frame: Assessing change between Baseline and Week 8
Change in Cognitive Function - Processing speed
Time frame: Assessing change between Baseline and Week 8
Chang in Cognitive Function - Attention
Time frame: Assessing change between Baseline and Week 8
Change in Cognitive Function - Inhibitory Control
Time frame: Assessing change between Baseline and Week 8
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Mar 2026.
- Background: PubMed 30349557Sardon Puig L, Valera-Alberni M, Canto C, Pillon NJ. Circadian Rhythms and Mitochondria: Connecting the Dots. Front Genet. 2018 Oct 8;9:452. doi: 10.3389/fgene.2018.00452. eCollection 2018.
- Background: PubMed 25389966Kohsaka A, Das P, Hashimoto I, Nakao T, Deguchi Y, Gouraud SS, Waki H, Muragaki Y, Maeda M. The circadian clock maintains cardiac function by regulating mitochondrial metabolism in mice. PLoS One. 2014 Nov 12;9(11):e112811. doi: 10.1371/journal.pone.0112811. eCollection 2014.
- Background: PubMed 24625643Kuzmiak-Glancy S, Willis WT. Skeletal muscle fuel selection occurs at the mitochondrial level. J Exp Biol. 2014 Jun 1;217(Pt 11):1993-2003. doi: 10.1242/jeb.098863. Epub 2014 Mar 13.
- Background: PubMed 23639403Anton S, Leeuwenburgh C. Fasting or caloric restriction for healthy aging. Exp Gerontol. 2013 Oct;48(10):1003-5. doi: 10.1016/j.exger.2013.04.011. Epub 2013 Apr 29.
- Background: PubMed 19796285Alexeyev MF. Is there more to aging than mitochondrial DNA and reactive oxygen species? FEBS J. 2009 Oct;276(20):5768-87. doi: 10.1111/j.1742-4658.2009.07269.x.
- Background: PubMed 29086496Anton SD, Moehl K, Donahoo WT, Marosi K, Lee SA, Mainous AG 3rd, Leeuwenburgh C, Mattson MP. Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity (Silver Spring). 2018 Feb;26(2):254-268. doi: 10.1002/oby.22065. Epub 2017 Oct 31.
- Background: PubMed 9042845Ferrucci L, Guralnik JM, Pahor M, Corti MC, Havlik RJ. Hospital diagnoses, Medicare charges, and nursing home admissions in the year when older persons become severely disabled. JAMA. 1997 Mar 5;277(9):728-34.
- Background: PubMed 8994496Fried LP, Guralnik JM. Disability in older adults: evidence regarding significance, etiology, and risk. J Am Geriatr Soc. 1997 Jan;45(1):92-100. doi: 10.1111/j.1532-5415.1997.tb00986.x.
- Background: PubMed 21529321Manini T. Development of physical disability in older adults. Curr Aging Sci. 2011 Dec;4(3):184-91. doi: 10.2174/1874609811104030184.
- Background: PubMed 18692159Chung HY, Cesari M, Anton S, Marzetti E, Giovannini S, Seo AY, Carter C, Yu BP, Leeuwenburgh C. Molecular inflammation: underpinnings of aging and age-related diseases. Ageing Res Rev. 2009 Jan;8(1):18-30. doi: 10.1016/j.arr.2008.07.002. Epub 2008 Jul 18.
- Background: PubMed 28432755Boengler K, Kosiol M, Mayr M, Schulz R, Rohrbach S. Mitochondria and ageing: role in heart, skeletal muscle and adipose tissue. J Cachexia Sarcopenia Muscle. 2017 Jun;8(3):349-369. doi: 10.1002/jcsm.12178. Epub 2017 Apr 21.
- Background: PubMed 22502861Tarasov AI, Griffiths EJ, Rutter GA. Regulation of ATP production by mitochondrial Ca(2+). Cell Calcium. 2012 Jul;52(1):28-35. doi: 10.1016/j.ceca.2012.03.003. Epub 2012 Apr 12.
- Individual participant dataSharing planned: Yes. Information on the study protocol may be provided upon request.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Stephen Anton, Ph.D. principal investigator
University of Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Time Restricted Eating Intervention in people with Aging, run by University of Florida at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Cellular Fuel Utilization (time frame: Assessing change between Baseline and Week 8). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05482711, which also lists 35 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Mar 2026.